massive reconfiguration time again.

the first thing I did was go a quarter turn lighter and that didn't seem to do anything but maybe I just hadn't gone enough... I reckon that's only getting half the vacuum signal if it needs to be split between two carburetors..
True, and your car brings another element to the equation - your car is a 4 speed. So, every time you floor it and let off to shift, those flaps are going to slam shut and then come flying open again. TQ's work this to perfection on clutch cars, however, I've not seen a pair (dual quads) working in harmony on a 4 gear car because I haven't seen them like that. I do think it can and will work. But you added to the tuning process